C3-Pee-O? New Robot Inspired by the Heart, Pumps Urine Instead of Blood

Nov. 8, 2013

By JON M. CHANG

A new pump powered by urine may find its way into eco-friendly robots in the future.

Peter Walters

A new advance in robotics is putting the Pee in C-3PO.

Researchers at the University of the West of England and the University of Bristol recently designed a robotic heart-like pump powered by urine. The robot, which also pumps the urine as it is drawing power from it, is likely to be implemented in a line of eco-friendly robots that run on biological waste.

Peter Walters, a researcher at the University of the West of England, has worked on similar robots that get their power from urine, but ran into some problems with how the urine was transported. "What happens is that the solid material precipitates out of the urine over time," he told ABC News. "Conventional pumps get blocked up."

Instead of relying on an outside motor to drive urine from point A to point B, Walters and his colleagues decided to make a heart-like structure that contracts and relaxes depending on the presence of an electric current. Urine is fed into microbial fuel cells (MFCs) that digest it and generate a small electric current in response.

That electricity is stored in a capacitor. After enough electricity has been collected, the capacitor discharges and the pump changes its shape. According to Walters, the pump consumes less than 50 milliliters of urine per day.

The end goal of Walters' robot, whose design and preliminary results were published today in the journal Bioinspiration and Biomimetics, is to be used to keep other MFC-powered robots running smoothly. "Conventional pumps for MFCs have a tendency to get blocked," he said. "Because this is simpler, it's less likely to break down."

As for what a pump-wielding MFC-powered robot would actually be capable of, Walters has some ideas. "The most recent developments have been to move back and forth along a set of rails and to sense its environment," he said. "We see these robots being used in a city environment, detecting pollution levels."

While the robots themselves aren't capable of doing much currently, the new pump is a big step forward. "Previous MFC robots have been powered by sewage sludge and rotting fruit," said Walters. "We're looking to urine as an untapped resource."

So, urine could be the next green source of robot fuel, or at least a yellowish-green power source.